William Paley, an Anglican archdeacon, wrote the most famous version of the teleological argument, or an argument that shows that the universe was created purposefully. His argument is that everything in the world has an intelligent design, or a design that fulfills a purpose (watch). In order to have an intelligent design, there must be an intelligent designer (watchmaker). Even if it is something we know nothing about, we can still tell that it is complex and that it has an intelligent craftsman.
There are arguments against his idea, which are about evolution. "Doesn't evolution explain natural design." No. We have always had intelligent designs but they change inorder to adapt to the new surroundings. Our bodies have such an intelligent design that they are always changing inorder to help keep us alive from disease or others by adapting to our surroundings.